#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
    int num = 0;
    while (scanf("%d", &num) != EOF)
    {
        if (num < 0)
            printf("0\n");
        else if (num > 0)
            printf("1\n");
        else
            printf("0.5\n");
    }
    return 0;
}